USP31 Knockout HAP1 Cell Line

The choice depends on the experimental question — though for USP31, this question has to come second to defining what those questions are. USP31 remains poorly characterized in the literature, and the Knockout line is most useful for unbiased discovery: identifying ubiquitination changes and pathways affected by USP31 loss without prior assumptions. Overexpression is more useful once candidate substrates are identified, allowing tests of sufficiency for deubiquitination. For initial characterization of USP31, the EDITGENE Knockout line in HAP1 is the higher-value starting point because emerging factors benefit particularly from clean loss-of-function genetics — the near-haploid background eliminates ambiguity from partial reduction effects. Discovery-oriented experiments (ubiquitin proteomics, transcriptomics) in the knockout are likely to be more informative than overexpression at this stage of characterization.

Primary applications: • Discovery ubiquitin proteomics: TUBE pull-down combined with mass spectrometry to identify proteins whose ubiquitination changes upon USP31 loss; foundational data for an under-characterized DUB. • Transcriptomic profiling: RNA-seq to identify downstream pathways affected by USP31 loss, generating testable hypotheses about its functional context. • NF-κB pathway studies: where preliminary data suggest USP31 involvement in NF-κB regulation, reporter assays and target gene expression analysis. • Substrate validation: candidate substrate identification followed by deubiquitination assays in vitro and in cells. EDITGENE recommends this model as a starting platform for functional characterization of USP31, an emerging factor in the USP deubiquitinase family.

Yes, and rescue experiments are particularly important for USP31 given its emerging status: • Construct design: use a codon-modified USP31 sequence with a C-terminal tag (FLAG, HA). For an under-characterized protein, both tag positions should be tested initially to confirm functional rescue. • Catalytically-dead rescue: an active site cysteine mutation is essential — for emerging factors, distinguishing deubiquitinase activity from non-catalytic functions is particularly important. • Discovery-oriented rescue: rescue with both wild-type and catalytically-dead constructs in parallel during phenotypic discovery experiments helps identify which phenotypes reflect USP31's enzymatic activity versus its potential scaffolding roles. • Functional readout: rescue should restore phenotypes identified in discovery transcriptomics or ubiquitin proteomics experiments. HAP1-specific considerations: • Diploidization: HAP1 cells gradually diploidize during extended culture — confirm ploidy by flow cytometry at the time of phenotypic assay. • Integration site sensitivity: position effects on transgene expression are more pronounced in near-haploid backgrounds; generating multiple independent rescue clones is strongly recommended. • Transduction efficiency: HAP1 transduces with lentivirus at moderate efficiency — increase MOI compared to standard immortalized lines.